Motivating the `flow network' terminology, [1]} proved that (REF ) is satisfied if \(P_F\)  arises from an edge flow function satisfying certain constraints. Namely, an assignment \(F:\mathcal {A}\rightarrow \mathbb {R}_{\ge 0}\)  of a nonnegative number (flow) to each action defines a policy via
\(P_F(t|s)=\frac{F(s{\rightarrow }t)}{\sum _{t^{\prime }:(s{\rightarrow }t^{\prime })\in \mathcal {A}}F(s{\rightarrow }t^{\prime })}.\) 
